Answer:
D
Step-by-step explanation:
d is not a function because if you do the vertical test for d
the line goes through it twice and if it goes through it twice it means it's not a function, D did not pass the vertical test
I put two pictures so you can see the difference. it shows you if it passed the vertical tesft or not. if you do not know abt the vertical test, you will learn abt it soon. a vertical test is very helpful to find out if it is a function or not. THE VERTICAL TEST CAN ONLY BE USED ON GRAPHS nothing more. I hope I helped.
